/**
 * Reference to 1017 Problem.
 */
#include <stdio.h>
#include <string.h>

int main(int argc, char *argv[])
{
	char s[32], buf[16], c;
	double x1, x2, re;
	fgets(s, 32, stdin);
	int i = 0, cnt = 0, len = strlen(s);
	while (i < len) {
		c = s[i];
		if (c == ' ') {
			buf[cnt] = '\0';
			x1 = atol(buf);
			cnt = 0;
			i++;
			continue;
		}

		buf[cnt] = c;
		cnt++;
		i++;
	}

	buf[i] = '\0';
	x2 = atol(buf);

	re = x2 - x1;
	if (re < 0) {
		re *= -1;
	}
	printf("%.0f\n", re);

	return 0;
}
